Connector for electric receptacles



Dec. 2s, 1948.

UK. HOE-HN 2,457,235

, CONNECTOR FOR ELECTRIC RECEPTACLEs' Filed 061;. 21, 1946 Karl H3223;

. attorneys Patented Dec. 28, 1948 UNITED STATES PATENT OFFICE $57,235 oomoron EOR'ELECTRIC anonmwcms ,Karl .Hoehn, Canto! Ohio 'Aprilicationfio'tbberZl, isms-swarm. rowan (cizas-csi' B Glahm. 1

The invention relates toxconnectors for: anchoringelectrical cables or insulated conductors to electrical receptacles, :-such 'as 1 outlet rboxes.

A :prior "conventional type of connector .embodies *a split clamp for securing the cable at the outside of the box and a "tubular exteriorly threaded 'stu'd extending through a knockout hole of the outlet box, there being a separate screw provided 'for drawing th'e split rclamp :parts togtherand 'a' 'nutfor screwing onthe stud? inside the "box to hold the connector in place. When such connectors are made rrom malleable castings, 'they are 'diflicult -to cast uniformly without defects which render them unsatisfactory.

n the other hand, when such connectors are formed fromsheet metal, their manufacture is relatively:complicated and expensive'because the tubular stud must be formed from a ilatblank and then swaged' and threaded by additional operations, 'ancl the split clamp 'must be perfora/ted and tapped. i

Regardless "of -how such "conventional 1 connectors'are-rnade, =each connector consistsof at least three loose parts which-require assembly'on the job, and alter the stud is inserted through a knock out hole in the outlet box'and the cable secure'd inthe stud by the split clamp, the nut must be slipped over the end of thecablescrewed on the inner-threaded-partof "the stud while it projects into' the box. Obviously, this is a difilcult operation because it is awkward to reach into *thecramped space within the box and start the nut on the threads of the stud with the fingers. =Moreover, when the time required for this operation is multiplied by thelarge number of outlet boxes'used in bulldingconstruction, the added labor cost becomes'a'substantial item.

It is therefore an object or the present invention to-provide a-novei connector for an electrica'l receptacle, which connector overcomes the disadvantages o'f prior constructions and is simple and inexpensive to manufacture.

'Another'object is to provide a novel connector which has-no loose parts requiring assembly on the "j ab 'and "apt to become lost or misplaced.

Anotherobjectis to provide a novel connector which is made entirely of sheet metal .without requiring any additional tapping, swaging or threading operations.

Another object is to provide a novel connector which is adapted to be .quickly .and .in'stantaneously securedin .the her: without screwing.

Aiiurther .objectisto provide-a novel -.connector in which' theelectricalcable is secured in posi- A still furtherxobiectjs to provide a novel "connector whichiis'quicklyssecured in an outlet box for securing an electrical cable, and which is adapted itOTQUiOkIY. release ithexcable and be easily removed from the box.

Finally, it; isran objecttof the present invention to provide a: noveli'andlimproved connector which is inexpensively manufactured from a minimum amountofrsheetmetal and which is quickly and easilyxinstalled ;.onthe job ,without requiring any tools.

" These :and iother objects are accomplished lby the; parts, elements, constructions, arrangements and combinations which comprise the present invention,1the natureiofiwhichiisset forthzin the followinmgenaral statement, :a preferrediembodi ment rof which :is "set fiorth' in the following :description and illustrated in tlre accompanying drawings, :and which is :particularly r and :distinctly pointed outmnd:sett-forth .in the appended claimsrforminglpflrtthereof.

In generalterms, thednvention may-berstated asincludingaa; generally rtubular sheet metal body having a :slotted*='top with; spaced uprightaears at one end and the other end being adaptedfforiinsertion through a knock-out :hole of an outlet box andrazlatchipivoted-in the tears Tfor swinging throimhntheaslotinto'ithe.body,1zsaid latch having an upwardly curved leg TifOl engaging under an upper *edge of the knock-"out hole and a :downwardly rcurved leg for :engaging :a cable passing through'theconnector'body into thebox.

Referring to the :drawing forming part hereof iniwhich a. preterrediemimdiment of 'the'invem tion is e-shown iby way mt :example;

Figure 1 is an enlarged detached isometric viaw of .therimprovednconnector, 'with: a portion of 1 one ear rbroken awayitorshowthetmanner "dfpivoting the latch therein;

:Rigj2tiszaqtransversezsectional*viewthrough 'an outlet'flaoxshowingthe novel '-connectorbeing insertedrin cone of Etireknock-out :holes cthereot ;-:Fig. i3 is arsimilar viewzshowing :the :novel connector :in position for securlnga cable massing into thetrbox; I

:Fig. :4 is 2 aysimilar'wiew'showing-the manner :6! removingrthewcable from-the rconnector; and

Fig. 5 is a detached isometriciview of 'ashi'm' for facilitating z=remcval of the "cable rfrom the connector. i

Similar -mnnerals refer ato similar parts throughout the wiews rot the drawing.

' The mitletlhoxmhown inzfizexlrawinpisrdi' :muai

construction and preferably includes a perforated bottom wall 6 with side walls I and 8 extending at right angles to the bottom wall. The side walls 1 and 8 are provided with the usual knockout disks 9 for forming when removed preferably circular knock-out holes ID in opposite side walls of the box, and electrical cables or conduits are led into the box through the knock-out holes ID.

The outlet box is preferably provided with attaching means which may be attaching flanges ll preferably located in diagonally opposite corners, one of said flanges being shown in the drawing, and an attaching screw l2 being threaded in each flange I I. The construction of the outlet box is well known, and is shown merely by way of example as being one form of outlet box to which the novel connector may be applied.

The connector preferably includes a tubular body l3 which is formed in a substantially cylindrical shape to fit rather closely within the circuiar knock-out holes in of the outlet box. Preferably, the connector is formed from a fiat blank of sheet metal which may be stamped out, and the upper edges M of the formed body are spaced apart to form a slot l5 extending longitudinally thereof. At one end of the slot a pair of ears l6 project upwardly therefrom, and the ears l6 are adapted to be positioned exteriorly of the outlet box when the other end of the body is inserted through one of the holes Ill thereof. Obviously, the body 13 of the connector may be made in any shape as required to fit into a knock-out hole which is not circular in shape.

The latch for securing the body member It in a. knock-out hole I is preferabl also formed of a piece of sheet metal, and is adapted for swinging through the slot i within the body member I3. The latch preferably includes an upper folded edge portion l1 having outwardly projecting tongues l8 which are rotatably or pivotally mounted in holes IS in the ears I6. Preferably, body member I3 is sufficiently resilient that the ears l6 can be sprung apart to allow insertion of the tongues I8 into the holes l9 from the insides of the ears, thus positioning the latch between the ears with the tongues pivoted in the holes 19 thereof.

As shown, the latch includes an upper leg 20 which is preferably of U-shape and curves downwardly from edge portion 8 and then upwardly to provide an upper flange portion 2i adapted to take under and engage behind the upper edge of the knock-out hole In in which the body member is inserted. Thus, the leg 20 provides for frictionally clamping the connector to the outlet box when the flange 2| is forced upwardly through the hole l0 and behind the upper edge thereof.

The latch is also provided with a lower leg 22 extending downwardly from edge H and having a downwardly curved portion 23 for extending into the opposite end of the body portion l3 and terminating in a beveled edge 24. The edge 24 is adapted for engaging and digging into the sur face of an electrical cable 25 passing through the body member l3 of the connector, as best shown in Fig. 3. As indicated in Figs. 2 and 3, the latch tends to swing downwardly by gravity, so that the beveled edge 24 of its lower 'leg is normally in a depending position.

In order to securely hold the connector in position within one of the knock-out holes m of an outlet box in the position of Fig. 3, means is preferably provided for fitting around the lower edge of the hole opposite to the upper leg 20' of 4 the latch. Such means may include a pair of spaced exterior projections 26 formed in the body member l3 in the side opposite the slot l5 by making indentations 21 on the interior surface thereof.

When the connector is inserted in one of the knock-out holes l0, it is tilted somewhat as indicated in Fig. 2, so that the bottom edge of the hole is positioned between the projections 26 before the front upper edge of the body member is inserted through the hole. After inserting the body member, the latch can be pressed inwardly from the outside to force the upper leg 2!! upwardly against the top edge of the hole until the edge is frictionally clamped by the flange 2i of the upper leg, in the position shown in Fig. 3. Thereafter, the end of the cable 25 may be pushed into the box through the body member l3, and the beveled edge 24 will slide 0; scrape over the upper surface of the cable covering as the cable is pushed inwardly. A slight pull on the outer portion of the cable will then force the beveled edge downwardly into the cable surface so as to securely hold the same, and the harder the cable is pulled the more the beveled edge 24 will dig into the surface thereof.

Accordingly, when it is desired to insert the end of the cable 25 into the outlet box and secure the cable in position, the operation is speedily performed without any tools, merely by inserting the novel connector in the required knock-out hole and then inserting the end of the cable through the connector. Thus, the cable is secured without requiring screwing on a nut on the inside of the box or tightening a clamping screw.

If it is desired to remove the cable from the box, the same is accomplished by inserting a thin shim 28 of sheet metal into the box from the outside and between the beveled edge 24 of the latch and the cable 25, in the manner shown in Fig, 4. By then grasping the shimv and cable, both the shim and cable can simultaneously be removed because the beveled edge 24 will easily slide over the smooth surface of the shim 28.

The novel connector is inexpensively made entirely of sheet metal without requiring any tapped holes or screw threads, is quickly and easily installed in an outlet box without requiring any tools, and has no loose parts such as screws or nuts which are apt to become lost.

In the foregoing description, certain terms have been used for brevity, clearness and understanding, but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such words are used for descriptive purposes herein and are intended to be broadly construed.

Moreover, the embodiment of the improved construction illustrated and described herein is by way of example, and the scope of the present invention is not limited to the exact details of construction.

Having now described the invention, the construction, the operation and use of a preferred embodiment thereof, and the advantageous new and useful results obtained thereby; the new and useful constructions, and reasonable mechanical equivalents thereof obvious to those skilled in the art, are set forth in the appended claims.

I claim:

1. A cable connector for an electric outlet box including a substantially cylindi body adapted at one end for projecting through a knock-out holeof the box, spaced upright ears on the other end of said body, and a gravity latch pivoted on said ears for swinging within said body, said latch having an upwardly curved leg for frictionally clamping the upper edge of said hole, and a downwardly curved leg for engaging a cable passing through said body.

2. A cable connector for an electric outlet box including a tubular body adapted at one end for projecting through a knock-out hole of the box, a latch pivoted in the other end of said body, said latch having a leg for frictionally clamping behind an edge of said hole, and said latch having another leg for engaging a cable passing through said body, whereby the cable can be forced into the box past the latch but the lower latch leg normally prevents withdrawal of said cable.

3. A cable connector for an electric outlet box including a tubular body adapted at one end for projecting through a knock-out hole of the box,

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Thomas Jan. 4, 1921 Number 

